1. Field of the Invention
The present invention relates to a knee-protecting airbag device which includes an airbag, an inflator for feeding the airbag with an inflation gas and a generally box-shaped case for housing the airbag and inflator and which case includes an airbag emergence opening at the bottom end region.
2. Description of Related Art
JP2013-119327A discloses a known knee-protecting airbag device which includes an airbag, an inflator which is generally cylindrical in shape and a case for housing the airbag and inflator. The case includes an airbag emergence opening at the bottom end region. The inflator includes a mounting bolt with which the inflator is mounted on the case, and the airbag is also mounted on the case with the aid of the mounting bolt of the inflator.
The airbag is mounted on the case with the mounting bolt of the inflator in such a manner that the cylindrical inflator supports a mounting inflatable region of the airbag, and the airbag emergence opening of the case is configured to be openable downward. With this configuration, the mounting inflatable region of the airbag is likely to protrude considerably downward out of the emergence opening in an initial stage of airbag deployment. In order to address this problem, the known knee-protecting airbag device is provided, on an outside of the mounting inflatable region of the airbag, with a tether that is fixed to the case by the opposite ends with a separate mounting means and located inside the case for covering an underside of the mounting inflatable region of the airbag and regulating the outer contour of the mounting inflatable region at airbag deployment.
However, since the tether is provided separate from the airbag, attached to the outside of the airbag and requires additional mounting work on the case, this configuration has a room for improvement in simplification.